This purpose of this proposal is to develop a cost-effective system to accurately and consistently monitor the position of an in-vivo catheter and provide real-time feedback throughout the operation. Intravascular ultrasound (IVUS) is an established technology for defining the amount of vascular buildup internal to arteries of the heart. The application of a low power radio frequency signal applied to the catheter cable shielding will permit accurate tracking of the catheter during operation. Real-time evaluation of the data by the physician or technician will be available and permit re-inspection of suspect areas prior to the conclusion of the operation. The final system will require no modifications to the existing IVUS catheters and the RF detection system will be integrated into the catheter table. All hardware will be transparent to the physician and require no modifications to current procedures and techniques for catheterization. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE